On Tuesday, airline shares fell after Delta reported a disappointing March PRASM gain of 2.2%, citing "lower close-in bookings driven by the sequester" as one of several factors. Delta led the decline, falling 8% to $14.94, while US Airways fell 4% to $15.74.

In early trading on Wednesday, US Airways shares were down 45 cents to $15.29.

Analysts had been expecting a March passenger revenue per available seat mile gain for Delta of 4% to 5.5%; Delta's guidance was at the low end of that range. At last month's JP Morgan transportation conference, Delta President Ed Bastian forecast a first-quarter PRASM gain of 4.5% to 5.5%, which implied a March gain of 4%. Delta has since reduced its quarterly guidance to between 4% and 4.5%.

Besides the sequester, Delta noted that its March PRASM gain was diminished by the impact of a weakening yen as well as "lower than expected demand as a result of our attempt to drive higher yields, and temporary inefficiencies during implementation of new revenue management technology." The negative trends offset PRASM gains in the trans-Atlantic and Latin markets, Delta said.

While US Airways PRASM was below gudiance, the carrier also reported that its March mainline passenger load factor was a record 86.1%, as mainline revenue passenger miles rose 5.1% on capacity growth of 3.2%.